Present audio signals do not provide the correct ratio, alignment, or order for the sound components contained within an audio signal to be heard as we would hear them in nature. The purpose of the present invention is to enable those same sound components, consisting of magnitude, frequency and phase, already contained, but hidden, within every audio signal, set free, to be heard, and experienced in a similar and like way as we would hear them in nature.
Prior art has devised many ways of enhancing an audio signal to bring out certain spatial and temporal information found in nature, but rarely heard in an audio signal. Most of these “signal processors” use various techniques, such as Inter-aural Intensity Differences (IID), Inter-aural Time Differences (ITD), Head Related Transfer Function Algorithms (HRTF), and other analog and Digital Signal Processing techniques, (DSP), that either add, and or subtract, information to the audio signal that isn't actually there. Other prior art signal approaches try to avoid tampering with, or altering the signal by utilizing polar, or phase layering techniques, such as the author's U.S. Pat. No. 8,259,960, which shows that by having sections of frequencies set to 0° polar phase, and other sections of the spectral bandwidth set to 180° reversed polar phase, that one can begin to establish a substantially complete audio signal without altering, or tampering with the original signal. Other means of non-additive, or subtractive measures that do not change or alter the signal through artificial processing means include utilizing mid-side, coincident, and or a form of Sum and Difference signal processing. Many of these techniques are limited to microphone capture to enhance the signal in production, and not to the post production of the signal itself. Another one of the author's U.S. Pat. No. 8,571,232, shows a unique “golden ratio”, based upon Ø. This ratio enables the quantity of spatiotemporal information within a signal to be heard closer to the way our ear-brain “hears”. But these, and other non-invasive signal processing techniques, only work with stereo or multi-channel systems and are therefore limited.
An ideal signal solution, as presented herein, would operate independent of need for any additional channels or redundant duplicate signals outside of its own internal process. It would perform monophonically, and would have an obvious spatiotemporal, life like, ‘presence’ even when played through a single loudspeaker. This is extremely important, as there is no other prior art capable of delivering a realistic sound over a single speaker; or, as in the case of commercial background music sound, distributed to many speakers via a single monophonic signal source. In this particular case, the present invention, when used in its monophonic or distributive application, solves a problem. Rather than disappearing through acoustical phase shifts, to become part of the added “noise” in an environment, the present invention can be heard through the noise, at any volume level, and acts like an ‘open-air-headphone’, enabling a kind of acoustic privacy curtain between tables at a restaurant, or experiential theme parks, outdoor shopping areas, and other large and small sound application needs for public spaces.
At another extreme, and of additional importance, the present invention, when applied to the world of the musical arts, sound recordings, film, television, and other high value audio venues, is the fact that the present invention neither adds nor subtracts any information of any kind, from the signal that isn't already in the signal. There is no artificial ‘effect’ processing of any kind.
This is very important, as nothing should ever be added too, or subtracted from the final created content—master, film, or the like which the artist, musicians, and producers didn't put in when originally created. And this is all the more important when we are dealing with historical archival masters, where works have been locked away and stored for posterity, long after the artists have gone.
In this regard, the present invention allows us to hear and experience all of the original direct and ambient sound of every recording ever made. Whether mono, stereo, multi-channel, or encoded. The original masters already contain all of the physical information the present invention is able to provide. In many cases, the only people whoever heard all of the sound contained in these records, were the actual artists, “before the glass” of the recording studio.
Additionally, while it is well known since the early days of stereo-sound recording, when attempts were made by record-labels, and equipment manufacturers to maintain viability and sales for ‘Mono’ records, that various forms to modify mono recordings, in order to compete with stereo, were made and various approaches were taken under a variety of names, including “enhanced stereo”, “pseudo-stereo”, and others. These techniques varied, but generally fell into one of two main categories, as indicated by prior art. One type split the mono signal and used frequency differences between the two new signals. The other, more popular, used a phase shift on one channel, and a correction circuit to make up for the magnitude and spectral cancellations. Through this day, these techniques, which have become a standard for those familiar in the art are used to enhance mono and provide mono with a spatiotemporal illusion.
Aside from extreme and invasive signal “effect” processors and DSP's, the ability to extract unprocessed additional spatiotemporal information from a pair of signals relies on one form of sum and difference, or phase layered methodology for a stereo signal and for ‘Mono’, a frequency based difference signal, or phase shifting one channel, leaving the reference signal alone in both cases. These have become the “tricks of the prior art trade”.
It is important to keep in mind that reversing polarity, or changing the quantities of L+/−R, and R+/−L will never impact mono. There are only two ways to impact mono for spatiotemporal ‘effect’ and, as mentioned, frequency signal processing, and/or phase reversal of one channel signal plotted against the reference signal.
The present invention is for a new approach to extract spatiotemporal information from a signal without concern as to whether or not it is mono, stereo, multi-channel, or even an encoded signal. It is agnostic to format and medium.